Why is my iMac suddenly slow after relocation?

Hi Neomi87

This is starting to sound like something near the iMac or something in-between the iMac and your router is causing Wi-Fi interference. Keep in mind that things like appliances, cordless phone base stations, high speed USB cables and drives, TV's, solid metal objects, etc.. can cause your iMac to have a poor or intermittent Wi-Fi signal.

see > Resolve Wi-Fi and Bluetooth issues caused by wireless interference - Apple Support

Your computer definitely isn’t slower because you moved it to another location in your room. Unless you are talking about WiFi/“internet” speed, and that could be due to signal strength at your computer’s new location.

If you are talking about your computer’s overall performance…. Have you updated to the latest version of MacOS? Any new programs downloaded lately? What kind of (if any) background activity does your computer have running?

I see your computer has only 8GB of RAM. I personally believe that is too little RAM for this day and age. I’d always tell the average computer user to look for 16GB minimum.

Buffering of videos that are on your hard drive, or ones you are streaming over the Internet (e.g., Netflix)? Voice chat I assume means FaceTime, Zoom, or something like that.

Sounds like maybe you are actually talking about network speed, latency or jitter. If you go to https://www.speedtest.net/ and run a speed test, what results do you get for download and upload speed, and ide, download and upload latency?

Hmm.. the iMac could just be in a weak or blind spot.

If possible, try moving the Wi-Fi Router or iMac over a foot or so to see if that helps.

Sometimes you have to draw an imagery line from the router to the iMac in order to figure out what might be blocking the signal path.

Something is likely interfering with the radio signals. Could be material in the walls; could be electrical wiring; could be another device...could be a combination of things and reflection and diffraction of radio signals creating varying interference patterns as a result.

The fact that your ping latency goes so high when your speed drops makes me think interference. I suspect that if you clicked on your wifi icon in the menu bar while holding the Option key, you would see that the MCS index for your connection was very low and the speed drop is related to the poor connection quality indicated by that number.

I again would advise you to do a fresh install of MacOS. Start fresh, see what happens afterwards.

By chance, is your router set to prioritize other devices in your network? (Check router settings)

As far as different devices performing differently in terms of speed…. That’s normal as different devices have different hardware which will perform differently. Devices with batteries will throttle hardware performance to conserve battery (that includes the WiFi radio). Etc.

Try a fresh install of MacOS and see what happens. If the issue continues, it could be faulty hardware acting up.

You can always try a fresh install of MacOS and see how things go from there. Just make sure you first backup and make copies of any important files/data before you proceed.

Being "slow" is up to interpretation. What do you mean by slow? Slow booting, slow in apps opening, .etc.

Your read and write speed seems satisfactory.

Write speed: 2099 MB/s

Read speed: 2600 MB/s

Your 8 GB of memory isn't necessary the cause of your perceived slowness. You can check that by observing the Memory graph of Activity Monitor and make sure it's in the green when you're experiencing slowness. If it stays in the green your memory is sufficient for the workflow.

Since we can't see your iMac nor are we clairvoyant you'll have to help us by describing in detail your concerns.

You are dangerously low on disk space, which can have a significant impact on performance.